History of AMAZAKE?

The origin of AMAZAKE theorised for Kofun period (B.C. 3 - 7 century) which is described on Nohon shoki (the most historiography written 710 - 794 earliest which exist)
Heian period (794 - 1185) it was chilled beverage for nobles in summer.
Muromachi period (1337 - 1573) it comes to sold commonly.
Edo period (1603 - 1868) AMAZAKE seller comes out. And came a seasonal tradition beverage for summer fatigue recovery. After then, it came to drink in coldest season to warm up.